But to do all this, Livingstone must have had a very clear perception of the course of duty. This is true. But how did he get this? First, his singleness of heart, so to speak, attracted the light: "If thine eye be single, thy whole body shall be full of light." Then, he was very clear and very minute in his prayers. Further, he was most careful to scan all the providential indications that might throw light on the Divine will. And when he had been carried so far on in the line of duty, he had a strong presumption that the line would be continued, and that he would not be called to turn back. It was in front, not in rear, that he expected to find the pillar of cloud and the pillar of fire. In course of time, this hardened into a strong instinctive habit, which almost dispensed with the process of reasoning.

In Dean Stanley's Sinai and Palestine allusion is made to a kindred experience,--that which bore Abraham from Chaldea, Moses from Egypt, and the greater part of the tribes from the comfortable pastures of Gilead and Bashan to the rugged hill-country of Judah and Ephraim. Notwithstanding all the attractions of the richer countries, they were borne onward and forward, not knowing whither they went; instinctively feeling that they were fulfilling the high purposes to which they were called. In the later part of Livingstone's life, the necessity of going forward to the close of the career that had opened for him seemed to settle the whole question of duty.

But at this earlier stage, he had been conscientiously scrutinizing all that had any bearing on that question; and now that he finds himself close to his home, and can thank God for the safe confinement of his wife, and the health of the new-born child, he gathers together all the providences that showed that in this journey, which excited such horror even among his best friends, he had after all been following the guidance of his Father. First, in the matter of guides, he had been wonderfully helped, notwithstanding a deep plot to deprive him of any. Then there was the sickness of Sekómi, whose interest had been secured through his going to see him, and prescribing for him; this had propitiated one of the tribes. The services of Shobo, too, and the selection of the northern route, proposed by Kamati, had been of great use. Their going to Seshéke, and their detention for two months, thus allowing them time to collect information respecting the whole country; the river Chobe not rising at its usual time; the saving of Livingstone's oxen from the tsetse, notwithstanding their detention on the Zouga; his not going with Mr. Oswell to a place where the tsetse destroyed many of the oxen; the better health of Mrs. Livingstone during her confinement than in any previous one; a very opportune present they had got, just before her confinement, of two bottles of wine [33]; the approbation of the Directors, the presentation of a gold watch by Captain Steele, the kind attentions of Mr. Oswell, and the cookery of one of their native servants named George; the recovery of Thomas, whereas at Kuruman a child had been cut off; the commencement of the rains, just as they were leaving the river, and the request of Mr. Oswell that they should draw upon him for as much money as they should need, were all among the indications that a faithful and protecting Father in heaven had been ordering their path, and would order it in like manner in all time to come.

[33] In writing to his father, Livingstone mentions that the wine was a gift from Mrs. Bysshe Shelley, in acknowledgment of his aid in repairing a wheel of her wagon.

Writing at this time to his father-in-law, Mr. Moffat, he said, after announcing the birth of Oswell: "What you say about difference of opinion is true. In my past life, I have always managed to think for myself, and act accordingly. I have occasionally met with people who took it on themselves to act for me, and they have offered their thoughts with an emphatic 'I think'; but I have excused them on the score of being a little soft-headed in believing they could think both for me and themselves."

While Kolobeng was Livingstone's headquarters, a new trouble rose upon the mission horizon. The Makololo (as Sebituane's people were called) began to practice the slave-trade. It arose simply from their desire to possess guns. For eight old muskets they had given to a neighboring tribe eight boys, that had been taken from their enemies in war, being the only article for which the guns could be got. Soon after, in a fray against another tribe, two hundred captives were taken, and, on returning, the Makololo met some Arab traders from Zanzibar, who for three muskets received about thirty of their captives.

Another of the master ideas of his life now began to take hold upon Livingstone. Africa was exposed to a terrible evil through the desire of the natives to possess articles of European manufacture, and their readiness for this purpose to engage in the slave-trade. Though no African had ever been known to sell his own children into captivity, the tribes were ready enough to sell other children that had fallen into their hands by war or otherwise. But if a legitimate traffic were established through which they might obtain whatever European goods they desired in exchange for ivory and other articles of native produce, would not this frightful slave-trade be brought to an end? The idea was destined to receive many a confirmation before Livingstone drew his last breath of African air. It naturally gave a great impulse to the purpose which had already struck its roots into his soul--to find a road to the sea either on the eastern or western coast. Interests wider and grander than even the planting of mission stations on the territories of Sebituane now rose to his view. The welfare of the whole continent, both spiritual and temporal, was concerned in the success of this plan of opening new channels to the enterprise of British and other merchants, always eager to hear of new markets for their goods. By driving away the slave-trade, much would be done to prepare the way for Christian missions which could not thrive in an atmosphere of war and commotion. An idea involving issues so vast was fitted to take a right powerful hold on Livingstone's heart, and make him feel that no sacrifice could be too great to be encountered, cheerfully and patiently, for such an end.

Writing to the Directors (October, 1851), he says:

"You will see by the accompanying sketch-map what an immense region God in his grace has opened up. If we can enter in and form a settlement, we shall be able in the course of a very few years to put a stop to the slave-trade in that quarter. It is probable that the mere supply of English manufacturers on Sebituane's part will effect this, for they did not like the slave-trade, and promised to abstain. I think it will be impossible to make a fair commencement unless I can secure two years devoid of family cares. I shall be obliged to go southward, perhaps to the Cape, to have my uvula excised and my arm mended (the latter, if it can be done, only). It has occurred to me that, as we must send our children to England, it would be no great additional expense to send them now along with their mother. This arrangement would enable me to proceed, and devote about two or perhaps three years to this new region; but I must beg your sanction, and if you please let it be given or withheld as soon as you can conveniently, so that it might meet me at the Cape. To orphanize my children will be like tearing out my bowels, but when I can find time to write you fully you will perceive it is the only way, except giving up that region altogether.
"Kuruman will not answer as a residence, nor yet the Colony. If I were to follow my own inclinations, they would lead me to settle down quietly with the Bakwains, or some other small tribe, and devote some of my time to my children; but Providence seems to call me to the regions beyond, and if I leave them anywhere in this country, it will be to let them become heathens. If you think it right to support them, I believe my parents in Scotland would attend to them otherwise."

Continuing the subject in a more leisurely way a few weeks later, he refers to the very great increase of traffic that had taken place since the discovery of Lake 'Ngami two years before; the fondness of the people for European articles; the numerous kinds of native produce besides ivory, such as beeswax, ostrich feathers, etc., of which the natives made little or no use, but which they would take care of if regular trade were established among them. He thought that if traders were to come up the Zambesi and make purchases from the producers they would both benefit themselves and drive the slave-dealer from the market. It might be useful to establish a sanatorium, to which missionaries might come from less healthy districts to recruit. This would diminish the reluctance of missionaries to settle in the interior. For himself, though he had reared three stations with much bodily labor and fatigue, he would cheerfully undergo much more if a new station would answer such objects. In referring to the countries drained by the Zambesi, he believed he was speaking of a large section of the slave-producing region of Africa. He then went on to say that to a certain extent their hopes had been disappointed; Mr. Oswell had not been able to find a passage to the sea, and he had not been able to find a station for missionary work. They therefore returned together. "He assisted me," adds Livingstone, "in every possible way. May God reward him!"